dt-bindings: display: Add bindings for EDT panel

Document the Emerging Display Technology Corp. (EDT) ETM043080DH6-GP
display, which is a 480x272 4.3" TFT display with capacitive touchscreen.

Changes in v2:
	-modify proper bindings file

Signed-off-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1580386118-22895-2-git-send-email-marian-cristian.rotariu.rb@bp.renesas.com